EN ISO 16474-3:2021

SLOVENSKI STANDARD
01-marec-2021
Nadomešča:
SIST EN ISO 16474-3:2014
Barve in laki - Metode izpostavljanja laboratorijskim virom svetlobe - 3. del:
Fluorescentne UV-svetilke (ISO 16474-3:2021)
Paints and varnishes - Methods of exposure to laboratory light sources - Part 3:
Fluorescent UV lamps (ISO 16474-3:2021)
Beschichtungsstoffe - Künstliches Bestrahlen oder Bewittern in Geräten - Teil 3: UV-
Fluoreszenzlampen (ISO 16474-3:2021)
Peintures et vernis - Méthodes d'exposition à des sources lumineuses de laboratoire -
Partie 3: Lampes fluorescentes UV (ISO 16474-3:2021)
Ta slovenski standard je istoveten z: EN ISO 16474-3:2021
ICS:
87.040 Barve in laki Paints and varnishes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16474-3
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2021
EUROPÄISCHE NORM
ICS 87.040 Supersedes EN ISO 16474-3:2013
English Version
Paints and varnishes - Methods of exposure to laboratory
light sources - Part 3: Fluorescent UV lamps (ISO 16474-
3:2021)
Peintures et vernis - Méthodes d'exposition à des Beschichtungsstoffe - Künstliches Bestrahlen oder
sources lumineuses de laboratoire - Partie 3: Lampes Bewittern in Geräten - Teil 3: UV-Fluoreszenzlampen
fluorescentes UV (ISO 16474-3:2021) (ISO 16474-3:2021)
This European Standard was approved by CEN on 17 October 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16474-3:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 16474-3:2021) has been prepared by Technical Committee ISO/TC 35 "Paints
and varnishes" in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2021, and conflicting national standards shall be
withdrawn at the latest by July 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 16474-3:2013.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 16474-3:2021 has been approved by CEN as EN ISO 16474-3:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 16474-3
Second edition
2021-01
Paints and varnishes — Methods
of exposure to laboratory light
sources —
Part 3:
Fluorescent UV lamps
Peintures et vernis — Méthodes d'exposition à des sources lumineuses
de laboratoire —
Partie 3: Lampes fluorescentes UV
Reference number
ISO 16474-3:2021(E)
©
ISO 2021
ISO 16474-3:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 16474-3:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 Laboratory light source . 3
5.2 Test chamber . 6
5.3 Radiometer . 6
5.4 Black-standard/black-panel thermometer . 6
5.5 Wetting and humidity . 7
5.5.1 General. 7
5.5.2 Spray and condensation system . 7
5.6 Specimen holders . 7
5.7 Apparatus to assess changes in properties . 7
6 Test specimens (panels) . 7
6.1 General . 7
6.2 Preparation and coating . . 8
6.3 Drying and conditioning . 8
6.4 Thickness of coating . 8
6.5 Number of test panels . 8
7 Test conditions . 8
7.1 General . 8
7.2 Radiation . 8
7.3 Temperature . 8
7.4 Relative humidity of chamber air . 9
7.5 Condensation and spray cycles . 9
7.6 Complex cycles with dark periods . 9
7.7 Sets of exposure conditions . 9
8 Procedure and mounting of the test specimens .10
8.1 General .10
8.2 Exposure .10
8.3 Measurement of radiant exposure .11
8.4 Determination of changes in properties after exposure .11
9 Test report .11
Annex A (informative) Spectral distribution of radiation for typical fluorescent UV lamps .12
Bibliography .16
ISO 16474-3:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 139, Paints and varnishes, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 16474-3:2013) which has been technically
revised. The main changes compared to the previous edition are as follows:
— in 7.2 the difference between the temperature of a black panel sensor and a black standard sensor
has been corrected;
— in Table 4 it has been changed that the black-panel temperature is not controlled during water spray;
— the text has been editorially revised and the normative references have been updated.
A list of all parts in the ISO 16474 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

ISO 16474-3:2021(E)
Introduction
Coatings of paints, varnishes and similar materials (subsequently referred to simply as coatings) are
exposed to laboratory light sources, in order to simulate in the laboratory the ageing processes which
occur during natural weathering or behind window glass.
INTERNATIONAL STANDARD ISO 16474-3:2021(E)
Paints and varnishes — Methods of exposure to laboratory
light sources —
Part 3:
Fluorescent UV lamps
1 Scope
This document specifies methods for exposing coatings to fluorescent UV lamps, heat and water in
apparatus designed to reproduce the weathering effects that occur when materials are exposed in
actual end-use environments to daylight, or to daylight through window glass.
The coatings are exposed to different types of fluorescent UV lamps under controlled environmental
conditions (temperature, humidity and/or water). Different types of fluorescent UV lamp can be used to
meet all the requirements for testing different materials.
Specimen preparation and evaluation of the results are covered in other ISO documents for specific
materials.
General guidance is given in ISO 16474-1.
NOTE Fluorescent UV lamp exposures for plastics are described in ISO 4892-3.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1514, Paints and varnishes — Standard panels for testing
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Terms and definitions
ISO 9370, Plastics — Instrumental determination of radiant exposure in weathering tests — General
guidance and basic test method
ISO 16474-1:2013, Paints and varnishes — Methods of exposure to laboratory light sources — Part 1:
General guidance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
ISO 16474-3:2021(E)
3.1
radiant exposure
H
amount of radiant energy to which a test panel has been exposed
Note 1 to entry: Radiant exposure is given by the equation:
HE=∫ ⋅dt
where
H is the radiant exposure, in joules per square metre (J/m );
E is the irradiance, in watts per square metre (W/m );
t is the exposure time, in seconds (s).
Note 2 to entry: If the irradiance E is constant throughout the whole exposure time, the radiant exposure H is
given simply by the product of E and t.
4 Principle
4.1 Fluorescent UV lamps, when properly maintained, can be used to simulate the spectral irradiance
of daylight in the ultraviolet (UV) region of the spectrum.
4.2 Specimens are exposed to various levels of UV radiation, heat and moisture (see 4.4) under
controlled environmental conditions.
4.3 The exposure conditions may be varied by selection of:
a) the type of fluorescent lamp (spectral power distribution);
b) the irradiance level;
c) the temperature during the UV exposure;
d) the relative humidity of the chamber air during the light and dark exposures, when test conditions
requiring control of humidity are used;
NOTE Commercial fluorescent UV lamp devices generally do not provide means of relative humidity
control.
e) the type of wetting (see 4.4);
f) the wetting temperature and cycle;
g) the timing of the UV/dark cycle.
4.4 Wetting is usually produced by condensation of water vapour onto the exposed specimen surface
or by spraying the test specimens with demineralized/deionized water.
4.5 The procedure(s) may include measurement of the irradiance and the radiant exposure in the
plane of the specimen.
4.6 It is recommended that a similar material of known performance (a control) be exposed
simultaneously with the test specimens to provide a standard for comparative purposes.
2 © ISO 2021 – All rights reserved

ISO 16474-3:2021(E)
4.7 Intercomparison of results obtained from specimens exposed in different apparatus or to different
types of lamp should not be made unless an appropriate statistical relationship has been established
between the different types of equipment for the material to be tested.
5 Apparatus
5.1 Laboratory light source
5.1.1 Fluorescent UV lamps are fluorescent lamps in which radiant emission in the ultraviolet region of
the spectrum, i.e. below 400 nm, makes up at least 80 % of the total light output. There are three types of
fluorescent UV lamp used in this document:
— The spectral distribution of radiation for typical fluorescent lamps is described in Annex A. Type 1A
(UVA-340) fluorescent UV lamp: These lamps have a radiant emission below 300 nm of less than 1 %
of the total light output and a peak emission at 343 nm. They are more commonly identified as UVA-
340 for simulation of daylight from 300 nm to 340 nm (see Table 1, Spectral pass-band column).
Figure A.1 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1A (UVA-340)
fluorescent UV lamp compared to daylight.
— Type 1B (UVA-351) fluorescent UV lamp: These lamps have a radiant emission below 310 nm of
less than 1 % of the total light output and a peak emission at 353 nm. They are more commonly
identified as UVA-351 for simulation of the UV portion of daylight behind window glass (see Table 2).
Figure A.2 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1B (UVA-351)
fluorescent UV lamp compared to daylight filtered by window glass.
— Type 2 (UVB-313) fluorescent UV lamp: These lamps have a radiant emission below 300 nm of
more than 10 % of the total light output, and a peak emission at 313 nm. They are more commonly
identified as UVB-313 (see Table 3). Figure A.3 is a graph of the spectral irradiance from 250 nm to
400 nm of two typical type 2 (UVB-313) fluorescent UV lamps compared to daylight. Type 2 (UVB-
313) fluorescent UV lamps may be used only by agreement between the parties concerned. Such
agreement shall be stated in the test report.
NOTE 1 Type 2 (UVB-313) fluorescent UV lamps have a spectral distribution of radiation which peaks near
the 313 nm mercury line and might emit radiation down to λ = 254 nm, which can initiate ageing processes that
never occur in end-use environments.
NOTE 2 The solar spectral irradiance for a number of different atmospheric conditions is described in CIE
[7] [7]
85 . The benchmark daylight value used in this document is from CIE 85:1989, Table 4 .
5.1.2 Unless otherwise specified, type 1A (UVA-340) fluorescent UV lamps or corresponding type 1A
fluorescent UV lamp combinations shall be used to simulate the UV part of daylight (see Table 4, method
A). Unless otherwise specified, type 1B (UVA-351) fluorescent UV lamps shall be used to simulate the UV
part of daylight through window glass (see Table 4, method B).
5.1.3 Fluorescent UV lamps age significantly with extended use. If an automatic irradiance control
system is not used, follow the apparatus manufacturer’s instructions on the procedure necessary to
maintain the desired irradiance.
ISO 16474-3:2021(E)
5.1.4 Irradiance uniformity shall be in accordance with the requirements specified in ISO 16474-1.
Requirements for periodic repositioning of specimens when irradiance within the exposure area is less
than 90 % of the peak irradiance are described in ISO 16474-1.
Table 1 — Relative ultraviolet spectral irradiance for type 1A (UVA-340) fluorescent UV lamps
a, b
for daylight UV (method A)
c d, e c
Spectral passband Minimum CIE 85:1989, Table 4 Maximum
(λ = wavelength in nm) % % %
λ < 290 — 0 0,1
290 ≤ λ ≤ 320 5,9 5,4 9,3
320 < λ ≤ 360 60,9 38,2 65,5
360 < λ ≤ 400 26,5 56,4 32,8
a
This table gives the relative values for irradiance in the given passband, expressed as a percentage of the total
irradiance between 290 nm and 400 nm. To determine whether a specific type 1A (UVA-340) fluorescent UV
...